
1) Concrete
Found on
https://www.crosswordclues.com/clue/litracon

LiTraCon is a trademark for a translucent concrete building material. The name is short for `light-transmitting concrete`. The technical data sheet from the manufacturer says the material is made of 96% concrete and 4% by weight of optical fibers, it was developed in 2001 by Hungarian architect Áron Losonczi working with scientists at the Techn.....
Found on
http://en.wikipedia.org/wiki/LiTraCon
No exact match found.